Process and means for producing carbon black



R. H. EAGLES 2,015,360

PROCESS AND MEANS FOR PRODUCING CARBON BLACK Sept. 24, 1935.

med Dec. 11, 1931 A INVENTOR -Re qinaZa'HE Zes Patented Sept. 24, 1935 PATENT OFFICE CARBON BLACK PROCESS AND MEANS FOR PRODUCING Reginald H. Eagles, Hastings-on-the-Hudson, N. Y., assignor, by mesne assignments, to J. M. Huber Corporation, Borger, Tex., a corporation of Delaware Application December 11, 1931, Serial No. 580,321

4 Claims.

My present invention relates to improvements in process and means for producing carbon black.

An object thereof is to improve upon the so- I called channel process which is today and for a longtime has been the recognized commercial method of manufacturing carbon black. This is because of the lack of a better process and in spite of its recognized inefilciency both as regards carbon recovery and its necessarily high cost of operation due to the many steel houses required for the multitude of small gas jets.

An object of the present invention is'to secure a better recovery of carbon black; also a more uniformly fine; particle product; also to produce carbon black-by a-more compact and less expensive apparatus and plant. I

An object of the invention is also to produce the black with a comparatively small number of relatively large burners permitting regulation in the amount of oxygen supplied to the combustible hydrocarbon gas for efflcient production of fine particle soot.

Another object is to produce the soot in the presence of an inert diluting and cooling stream of gas or gasesregulated both as to quantity and temperature to cause the'soot to retain as far as possible the fineness of its particles as originally produced at the burners.

These and other objects and advantages of the invention will 'morefully appear from the following description in connection with the drawing.

The herein process is adapted to be carried out with various forms of apparatus including that shown diagrammatically in the accompanying drawing. However, it will be understood that the process is not limited to any particular form of apparatus but may be practised with various kinds and adaptations of apparatus suitable for the purpose.

In the drawing, Fig. 1 is an elevation with parts in section illustrative of a form of apparatus for practising the process of the invention; Fig. 2 is a fragmentary view, partly in vertical section, on an enlarged scale of a portion of Fig. 1 relating to the burners; Fig. 3 is a fragmentary horizontal plansection on the line 3-3 in Fig. 1 on an enlarged scale; and Fig. 4 is an enlarged vertical cross-section of a fragment of the perforate plate of Fig. '1. v i Referring to the drawing, I is a box or chamber of suitable material through the bottom of which project burners 2 preferably with arrangement for vertical adjustment. Each burner is shown as comprising a pair of concentric pipes, the inner 5 pipe 2' for the de i e y of a hydrocarbon gas and the outer pipe 2 for the delivery of an oxygen-bearing gas such as air. A valve is provided as shown in connection with each pipe for delivering the proper relative amounts of oxygenbearing and combustible gases to produce sooty 5 flames with eflicient production of fine particle soot or carbon black.

The lower part of the chamber I may be substantially rectangular in horizontal cross-section and contains a plurality of burners which may be 10 arranged in rank and file formation. The individual burners are of such size as to burn the combustible gas with large sooty flames.

- The pipe 3 is a gas-supply main connected to all of the gas tubes of the burners; and the air- 15 supply main 4 connects with all the air tubes of the burners to supply air thereto. Each of these mains is provided or equipped with a valve 21 and a gas-flow meter 28.

The upper part of the chamber I may extend 2o beyond the end of the aforesaid lower part; and the walls of said upper part may converge as shown to a neck I suitable for connectionto the inlet of a rotary fan 5. The chamber I has an inlet I for delivering into the chamber a 25 stream of inert gas to dilute and cool the gaseous combustion products and the carbon black particles coming from the burners. This stream of relatively cool inert gas immediately dilutes the gaseous combustion products and increases the 30 spacing between the soot particles and simultaneously cools them so that their tendency to agglomerate into larger size particles is inhibited, and moreover said stream of gas carries the particles along, horizontally, helped by the fan 5, 35 which delivers the stream of gases and cooled soot particles into the flue 8 and into the bag compartments 1. For this purpose, the flue has branch pipes Ii provided with valves. The ends of these branch pipes lead air-tight into the ver- 40 tical compartments 1. Within each compartment is a bag 8 of a suitable textile material or fabric whose mouth is attached to theend of the given branch pipe 6* of its compartment.

The lower end 8" of each bag is releasably closed. 45

A flue I2 connects the gas delivery end of condenser II to the intake of a rotary fan II, the outlet of which is connected by a flue I4 controlled by a valve IS with the previously described inlet I of the chamber I.

A wire mesh screen, perforate plate or other form of reticulated member I6 may be interposed more or less horizontally between the lower and upper portions of the soot-producing chamber I. This member extends across the upper portions of the flames and 'prevents the previously referred to stream or draft of diluting and cooling inert gas from unduly disturbing the flames andoperation of the burners.

The operation of the process is as follows: A hydrocarbon gas, which preferably may be socalled natural gas, is supplied to the burners and kept continuously burning in the chamber I with just enough oxygen supplied by the pipes 2 to maintain combustion with maximum production of flne soot particles. The illustrated and described construction enables the supply of oxygen to be regulated relatively to the hydrocarbon gas to produce this desired result. The oxy enbearing gas may be and preferably will be atmospheric air. In other words, the hydrocarbon gas is burned in the chamber I in the presence of a limited amount of air to produce the maximum amount of flnely divided soot particles. The products of combustion from the sooty flames and the unconsumed or non-combustible nitrogen portion of the atmospheric air and' the soot particles are delivered into the upper part of the chamber where they are immediately diluted and cooled by the stream of inert gas delivered by the inlet I flowing across the chamber and exiting through the outlet I.

By "inert" gas is meant any oxygen-deficient gas having no chemical effect in the process. The inert gas preferably employed will be the mixture of gases derived from the combustion of the hydrocarbon gas in the presence of air in the burner chamber I after the carbon black particles have been separated therefrom.

The dilution derived from the stream of inert gas is such that the spacing between the soot particles is increased and the tendency is inhibited of the freshly formed soot particles to agglomerate into larger size particles. Also, the temperature of the diluting inert gas is such as to reduce the temperature of the soot particles below that at which they agglomerate into larger size particles. By the time the soot particles have been blown into the bags I, they have become so cool that they will not agglomerate into larger size particles, whereby the desirable flne particle size of the carbon black is maintained in the flnal product recovered from the bags.

The volume and flow of the diluting inert gas is controllable by valve II and is indicated by the meter 30 in the flue line I4. A pyrometer 26 extending into the upper portion of the chamber I enables observation of the resultant temperature of the intermingled diluting gas and the products of combustion whereby the temperature of the incoming diluting gas can be adjusted to maintain a temperature in the upper part of the chamber I at which the carbon black particles will be rapidly cooled to a non-agglomerating temperature. This resultant temperature will be within a temperature range of 300 to 500' I". This temperature must be low enough to substantially inhibit soot particle growth and must be high enough to prevent the condensation of the water-vapor produced in large quantity as a by-product from the burning of the hydrocarbon gas.

It will be understood that it is possible to dispense with the reticulated member It and provide other means or some other arrangement than that shown to attain the same object whereby the flames will be allowed to produce their flne soot particles efficiently without substantial interference from the draft of inert diluting and 10 cooling gas. v

The quantity of inert gas in the apparatus is constantly increasing because it is derived from the combustion of the constantly supplied hydrocarbon gas in the constantly supplied air. Therefore, means is provided for getting rid of the unwanted excess of inert gas, said means comprising a blowvofl' device II to maintain the quantity of inert gas approximately constant needed for the working of the process. The meter III in the flue line It indicates the quantity and rate of flow of inert gas for diluting and cooling the products of combustion and the carbon particles derived from the burners. The quantity and rate of flow of said gases are controllable by regulating the valves of the flue line and the speed of the fans. A thermometer II registers the temperature of the inert gas supplied to the chamber I.

The thermometers I I in the respective bag compartments I register the temperature of the gases flowing through them whereby the operator can be sure that a temperature is maintained therein above the water-vapor condensation point so that the carbon black collectingin the bags will be dry.

A thermometer 20 in the flue I2 at the exit from the condenser shows the temperature of the cooled dry inert gases coming from the condenser.

If this temperature be too low so that. the prod- 40 nets of combustion in the chamber I would be cooled too much, the inert gases delivered by the blower it through the flue Il may be heated to a suitably higher temperature as required by putting into operation the heating device 2i through which the flue passes. This heating device ordinarily will not have to be used and may comprise any suitable form of heater for heating the gases as they are carried through the flue II. Thus, this heater may consist of.a chamber enclosing the flue into which a heating medium can be introduced such as superheated steam or hot gases; or the flue may be heated directly by means of gas burners or other form of direct heating 11188118. The reticulated or perforated member I! may I be hollow as at It (Fig. 4) so as to provide connecting passages to enable the member to be internally cooled to a preferred temperature by circulating through it a cooling stream of air or water of regulated temperatiue.

In the drawing, the apparatus happens to be arranged in a closed system, although this is not essential as will be hereinafter explained. The soot-bearing gas is blown by the fan or fans into the particular bags whose valves are open. The soot is deposited within the bags and the gases are forced through the pores of the bags and out of the compartments I through the pipes 0' and flue I through the condenser II which may be of any suitable type for removing the water-vapor from the gases, which is then automatically delivered from the condenser by means of a device I I or the like.

Therewillbe apluralityorbatteryofthecol- 7s lecting bags 8 with their compartments I, only two being shown in the drawing. While some of them are in operation with the valves 6 open, others will be out of operation with their valves closed, so that they can be emptied of their carbon black contents, This will be accomplished by opening up the closure ii at the bottom of the given bag and emptying its contents through a suitable opening in the bottom of the compart ment I (not necessary to be shown in the drawing), said opening being ordinarily sealed by a door. As a preliminary to this, the valve 9' of the outlet 9 of the particular compartment, will be closed so as not to interfere with the circulation of the gases, etc., in the rest of the apparatus or with the operation of the process.

The resultant process as described above is cyclical and the apparatus forms a closed system, but it will be understood that this is not at all necessary. Thus, the gases derived from the bag compartments may be delivered into the atmosphere instead of being returned back into the process. In this case, the cooling gases may be derived from some other convenient or desired source and delivered therefrom into the burner chamber l.

Instead of the bag system, other means may be used for collecting the carbon black, such as electric precipitation in conjunction with a cyclone air separator, a portion of the carbon back product being recovered from the electric precipitation part of the apparatus, and the remainder from the cyclone separator.

What I claim is:

1. Carbon-black process which comprises burning a carbonaceous gas with production of fine particle carbon-black suspended in the gaseous products of combustion, and immediately delivering the gaseous products of combustion and the suspended carbon-black particles through a screen and into a stream of inert gas serving to cool and dilute the gaseous products suiiiciently to inhibit the agglomeration of the carbon-black particles.

2. Carbon-black process which comprises burning a carbonaceous gas with production of fine particle carbon-black suspended in the gasgaseous products of combustion and the soot particles sufliciently to inhibit the agglomeration of said particles; and a perforate member in said chamber between the burner means and the means for delivering the stream of inert gas preventing the latter from substantially interfering with the operation of the burner means.

4. Apparatus for making carbon-black comprising a chamber, means in said chamber for burning a hydrocarbon gas with limited oxygenation to burn with soot-producing flame, means I .for delivering a stream of relatively cool inert gas through the chamber to dilute and cool the gaseous products of combustion and the soot particles suiiiciently to inhibit the agglomeration of said particles; a perforate member in said chamber between the burner means and the means for delivering the stream of inert gas, said perforate member being hollow for the circulation of a cooling medium therethrough.

REGINALD H. EAGLES. 

